The Green Machine's charts are all written by the students that are in the band. If they want to play new music, Doc always gives them the opportunity. All it takes is a student with drive to write/arrange it.
That being said, the DJ is taking up a significant amount of their air time, so even if they have new music they might not be able to play it.
That being said, the DJ is taking up a significant amount of their air time, so even if they have new music they might not be able to play it.